The present invention relates to modular conveyor belts and chains, and more particularly to a conveyor module which can support rollers and a modular conveying assembly including at least one of the conveyor modules.
Modular belting and chains are formed from interconnected modules that are supported by a frame and driven to transport a product. Each module has a support surface which supports the product as the belting or chain is being driven along the frame. Adjacent modules are connected to each other by hinge pins inserted through hinge members extending from adjacent modules in the direction of the belt travel. Roller are often incorporated into modular belts to reduce friction between the belt and frame or reduce back line pressure on the conveyed product. Incorporating the roller into the belt has taken different forms.
One known solution for reducing back-line pressure is disclosed in U.S. Pat. No. 4,231,469 issued to Arscott. In Arscott, rollers are supported by roller cradles between modules. The rollers extend above the cradle for rolling contact with an object being conveyed independent of the location of the hinge pins. The rollers reduce friction between the belt and the object. Unfortunately, assembling the roller in the cradle is difficult, requiring insertion of the roller into the cradle, and then slipping an axle or two stub axles through holes formed through the cradle walls and into the roller. The axle must then be secured to prevent it from slipping out of one of the holes formed in the cradle wall. This particular solution has many parts and is difficult to assemble.
Another known solution to this problem is to rotatably mount rollers directly on the hinge pin connecting modules together, such that the hinge pin supports the rollers between adjacent hinge members. The roller rotates about an axis of rotation that is substantially coaxial with the hinge pin axis. Assembling a modular conveyor including modules having a pin supported roller between adjacent hinge members is labor intensive. Each individual roller must be held between the adjacent hinge members as the hinge pin is fed through the coaxial openings in the hinge members and rollers. Moreover, when the modular conveyor is disassembled, once the hinge pin is removed, the rollers tend to fall away and are lost, or worse cause a loss of time, mechanical damage, or product contamination. A need exists for a conveyor module which can support a roller between adjacent hinge members without a hinge pin to simplify modular conveyor assembly and disassembly.